In manufacturing reinforced elastomeric products, it is essential that the reinforcing means adhere to the elastomer. This is conventionally accomplished by first treating the cord or the fabric with an adhesive, such as an RFL. The material may then be subjected to a topcoating, and eventually the cord or fabric is embedded in elastomer.
U.S. Pat. No. 6,764,422 (Hasaka et al) discloses a number of methods of treating a fabric. The disclosed methods include various combinations of pretreating with an epoxy compound, adhesion treating with RFL consisting of an elastomer latex, and overcoat treating with a rubber adhesive prepared by dissolving a rubber in a solvent. While this produces a cord that bonds well, the adhesion treating and the overcoat treating use either latex or a solvent. When using such treatments, the liquid in the latex solution or the solvent must be evaporated or otherwise removed, creating an additional step in the fabric processing and requiring additional machinery to remove and handle the removed liquid or solvent.
The viscoelasticity of useful elastomers is somewhat reduced by heat and shear generated by calendering, but not to the same extent achieved by solvation. The calender can apply the elastomer at higher pressure and the softening elastomer can penetrate the larger interstices near the surface of the fabric or cord but not the smaller interstices of the fabric or cord. Even when softened, the unvulcanized elastomer has a significant elastic component of the viscoelasticity that reduces penetration of small cavities.
The encapsulating material on the outer surface of fabric on the surface of the elastomeric product may also need to have properties of oil resistance, wear resistance, ozone & heat resistance, coefficient of friction, depending on the function of the reinforced article.